I may be wrong, but I believe that the oem bore for the 5.7L LS1 is 3.898"?

EDIT: Found a source...

ENGINE: Liters: Cubic I: Bore: Stroke: Rod Length: Comp:
LR4 4.8 293 3.780 3.268 6.276 9.5
LM7 5.3 325 3.780 3.622 6.098 9.5
LS1 5.7 346 3.898 3.622 6.098 10.1
LS6 5.7 346 3.898 3.622 6.098 10.5
LQ4 6.0 364 4.00 3.622 6.098 9.4

 

I hear mixed results on this... But thanks for correcting me if I'm wrong. Either way, if I were to bore the engine out more then .040", the next biggest piston I can get is for a LS1, without having one custom made. Reguardless if it's a 3.898" or 3.903" bore, it's a hell of a lot more then .040" over.

 

It is my understanding that GM designed and cast the 5.3 block to have the capability to be a 5.7 as well. They just never put it into production. That's why there have been no problems with taking them that far over.

 

So what is the stock stroke of the 5.3's crank and what is the most they can be bored to? can 4.00 inch bore be achieved?

 

Stroke is 3.622 stock, and no you can't go to a 4" bore. 3.903 is pretty much the limit. You need a 6L block for a 4" bore

 

well hot damn, provide me with a link, summit or jegs don't carry them.

 

summitracing.com or jegs.com

 

Sounds like you're going after some pretty serious HP. I wouldn't even consider doing a project like this starting with a 4.8/5.3L block. You'll likely replace everything in the block and just use the block....right? How much, % wise, would it cost extra to start with a better block? I bet a small % compared to the whole project. Sounds to me like you need to start with a 6.0L block and use that 4.8 for a boat anchor. I've been told they'll hold a sizable boat in some pretty deep and stormy waters........

 

Here's a link to the Mahle Catalog. It's in PDF form.
http://www.mahle.com/obj.nsf/79F2ED4E66CA2DE1C1256BC80056FA3C/$FILE/Mahleinc_cat03_21_02.pdf

 

Last time I looked, 6.0L blocks were around $600.